The WAAS, EGNOs, and MSAS GPS Augmentation Systems bridge the gap between the military applications of GPS and the needs of civil aviation navigation. These USA, Europe, and Asian systems consist of a network of differential GPS ground stations, using principally the Inmarsat-3 geosynchronous satellite constellation as the means of relaying the differential corrections to the users. In the process of providing precise navigation signals, GPS time is maintained through the Inmarsat-3 downlinks. It is this functionality that provides fist robust time retrieval for the synchronization needs of the telecommunications community. This paper discusses: 1) The basic makeup and performance of the system 2) How time and frequency can be extracted for the telecom terminals 3) Added functionality and noise rejection capabilities using these signals for telecom timing applications 4) How the system offers the first true backup to the GPN C/A signal for telecom synchronization users.